}


    /**
     * 
     */
    void markDomainDfs () {
        this.inDomainDfs = true;
    }


    /**
     * @return whether this tree was accessed using domain DFS
     */
    public boolean isInDomainDfs () {
        return this.inDomainDfs;
    }


    /**
     * @param referral
     */
    public void setTreeReferral ( DfsReferralData referral ) {